My experience of the NHS was rather upsetting like yours.
I was dx with BPD. I remember sitting in aftercare from the detox I'd been in and crying, feeling hopeless. I mean who wants a dx like that!!

The psychiatrist assessed me. Said medication would be of no benefit to me and said come back in 6 months.

Fast forward. I crashed. The treatment centre gave me a card of a private therapist.
15yrs later in still with her. She said I didn't have BPD and even if I had, it wasn't untreatable. Though she knew a lot of people prefer not to work with with that dx. Not her by the way.
So. Find a private therapist who has a sliding scale.
I look back at my NHS experience and think I could teach them a thing or 2. But hey. Life goes on.